VLAN update (by alaric)

Ok, suspecting that the MTUs might be a problem, I put an fxp ethernet card into the single PCI slot in my home server (ousting the SCSI card), since that card can support the large Ethernet frames required to have a standard 1500 MTU plus 802.1Q VLAN tags.

But, alas, things were little better. From a desktop machine wired into the same switch as the server I still can't do DAAP without iTunes randomly closing the connection in mid-stream, and from Sarah's laptop on the wireless LAN, she still can't do DAAP or reliable SMB file sharing (the connection keeps getting dropped). SMB seems OK from the desktop machine, however.

So I wondered if NetBSD's 802.1Q implementation might be the problem; since the old vr interface is built into the server's motherboard, I now have two NICs, so just put the server on both internal VLANs independently (with no 802.1Q). And it's no better.

I can imagine that iTunes might just be fussy about its DAAP implementation and not like something daapd (an open-source implementation of the DAAP music sharing in iTunes) is doing; but why should SMB also be unreliable? I tried SMB from my own laptop over the wifi link, and found it workable but oddly slow. I'm going to experiment further with connecting my laptop directly to the switch (on either wifi or internal VLAN) and seeing how it responds, I think... something's fishy!

VLAN woes (by alaric)

At our house, we have three LANs; the external one, which is connected to the ADSL router and has a range of six public IPs; the internal one, which is joined to the external one via a NAT router (so using a single public IP) and contains my workstations and the fileserver; and the guest one, which is bridged to wireless Ethernet - and also joined to the external network via the NAT router.

Now, since I've not cabled the place yet, the physical layout of the network is dictated by the lengths of the cables I have. The ADSL router is at one end of the building, near the phone sockets, while the workstations are right at the very other end of the building. Therefore, the NAT router is in the airing cupboard, roughly in the middle of the building; my longest cables reach from the ADSL router to the NAT router, and from the NAT router to a switch in the office from with the workstations and server connect; and the wireless bridge sits in the airing cupboard along with the NAT router.

Even when I have structured cabling in place, I don't want to be having to cable three separate LANs around the house anyway; the natural solution is to use VLANs. That way, you can have switches joined by single-cable trunks, and those trunks carry all of the LANs in one; at each switch, you can either configure a port to connect to a specified VLAN, or configure the port to use IEEE 802.1Q tagging to connect a machine that understands it, in which case that machine can join whichever VLANs it is allowed using the single cable. This saves on the cabling a great deal.

Xen (by alaric)

I'm seriously considering becoming a big user of Xen. As in, making all of my servers run Xen (with NetBSD as the host OS), with everything of import then running in Xen "domains" (virtual servers) beneath.

There's a number of advantages to this. Read more »

Eyes (by alaric)

When I was quite young (5 or so?) I remember having conjunctivitis - rather vividly, since it involved my eyes being stuck shut in the mornings and having to be cleaned out by my mother before I could open them. And, alas, I have it again; this morning, my wife had to clean my eyes up before I could see...

So when I could see well enough, we went and got this 'eye ointment' stuff that she had to put in my eyes (holding me down as she did it!), and afterwards, my eyes felt very sensitive so I sat there for some time with them closed.

This brought to mind a long-running area of interest of mine, which is the design of computer interfaces that are usable to the blind. I only see usefully with one eye anyway, so if anything should happen to the other eye, my career in software development will rather depend on such software...

Going Live! (by alaric)

It's not often that I get to actually write about my work other than tangentially, since it's usually somebody's trade secret, but for a long time now I've been doing the technical architecture and some of the programming for an actual publically viewable web site; and it's been under wraps during development, but now the site is soft-launching, I can start telling people about it.